Microsoft did purchase Qdos, and there are direct correlations between qdos and msdos. What the article asserted was that there is no cp/m in qdos, nor is there any cp/m in msdos. There certainly is plenty of qdos in msdos.

It's fine if MSDOS contains parts of QDOS if Microsoft bought QDOS. The original authors got paid. Now if we consider the price paid to be fair is another story... But that doesn't matter, all that matters is did the author think it was a fair price at the time, and did he willingly accept it? In hindsight, of course he should have gotten more, but that is always the risk when you sell your IP...

He didn't even swindle it. Microsoft paid for it outright, source code and all license rights. So it really doesn't matter if it was exactly the same. It's not Gates' fault that the other guy didn't have a buyer like IBM waiting.

Who is this "everyone" that is "surprised" that you only license Windows? Even with FOSS, you only have a license - you do not "own" the code. There can be only one owner of a thing, and in the case of Windows, that owner is Microsoft.

I think if you research it carefully you will find that just about any "public commons" is owned by a government organization or agency. Like the Washington Monument is likely owned by the National Park Service.

Sure, it is "licensed" so that it can be used by people with some restrictions, just like anything else in the software world. However, if this were not the case and it was owned collectively by everyone it would be impossible to block people putting up tents on the Mall - because they would be "ow

Gate's bought the DOS operating system and sold IBM a License. He didn't sell them the damn code.

No, he bought QDOS, renamed it to MS-DOS, and licensed it to IBM as IBM PC-DOS.

Er... I don't follow you. QDOS was DOS, the first version of DOS. So Gates did buy DOS.

That is not to say that MS did not greatly modify and improve it, even by the time it was sold with the first IBM PC as PC DOS.

The "QD" stood for "Quick and dirty". IT companies still had a sense of humour then. Grim Gates helped to change that though. The name QDOS was succeded by prefix DOS where the "D" now stood for "Disk" and prefix could be MS, PC and even DR or Caldera.

Now nothing was illegal - but my god. What a complete lack of any decent human characteristic.

I'm no Bill Gates fan, but that's a hard case to make. He had information that both IBM and Brock lacked, and without that information, Brock might never have made any money on the product. There's no denying that his mother's connections to IBM folks made that happen for him, but he was the essential link in the chain (even if not a very talented one). It's those essential connections where profit happens.

Gates gave SCP a decent payday (explicitly an acceptable price to Brock) and then gave Patterson a job three times, and bought Patterson's company from him. Heck, Patterson was such an early Microsoft employee that he could have made (did make?) a killing on its stock. SCP made healthy independent profits riding on the coattails of Microsoft's IBM-PC success, but then sued them for more profits, which only wound up in a settlement. Since we're judging all this in hindsight, Brock would have been better off joining Microsoft with Patterson if he wanted to share in its profits.

There's no denying that his mother's connections to IBM folks made that happen for him

Grow up.

Microsoft was selling microcomputer BASIC to the Fortune 500 in 1975. By 1980 it had a full suite of languages ready for porting to the 16 bit micro --- MBASIC, FORTRAN, COBOL, PASCAL, and, I believe an assembler.

The Z-80 Softcard for the Apple II would became the primary distribution channel for CP/M.

By any standard, the SoftCard was a hugely successful and highly visible product.

In XENIX Microsoft had a plausible entrant in the *NIX market.

MBASIC was an industrial award-winner as the first million-dollar bestseller for the microcomputer.

A company on the move. Willing to take chances. Willing to cut a deal. None of this could possibly have passed unnoticed by the small, quick and agile IBM PC development team.

In 1980, she discussed with John Opel, a fellow committee member who was the chairman of the International Business Machines Corporation," her son's company. "Mr. Opel, by some accounts, mentioned Mrs. Gates to other I.B.M. executives. A few weeks later, I.B.M. took a chance by hiring Microsoft, then a small software firm, to develop an operating system for its first personal computer."

Insider trading isn't "considered" illegal, it IS illegal - there is a law against it. It is illegal because that is the rule for being a publicly traded corporation - everyone gets info affecting the price of the stock at the same time. If that were not the case, people inside the company could profit at the expense of the other shareholders.

None of that has anything to do with private dealings. In fact, it is likely that Gates was under an NDA and could not say anything about the IBM deal, as IBM had not yet announced the PC. Divulging the IBM deal could not only have insider information ramifications, but remember that at the time IBM was under a consent decree that prohibited them from 'pre-announcing' anything.

If that were not the case, people inside the company could profit at the expense of the other shareholders.

Sure. Now why do we think that's wrong? What's the problem with allowing people inside the company to take advantage of the outsiders.? Couldn't the outsiders also get jobs within the company if they chose? Why is the asymmetric information considered a problem?

You're about to come back to me with some variation of the idea of fiduciary duty, which is simply restating the question. Why would they have a fiduciary duty to the stockholders? Why do we care if one group of people with superior information take advantage of another group of people? After all, anyone could get a job at the company. Anyone could -- in theory -- also become privy to the inside information. Why do we protect the shareholders from the reality of the market? What's the problem with asymmetric information in a capitalist market, and why do we feel the market distortions they cause to be evil?

When you get that answer, apply the principal to private dealings. Johnny Depp plays an evil man in "The Ninth Gate," a rare book dealer who visits bereaved families and buys rare books from the estate before the family realizes how valuable the books they sold are. The audience considers this to be evil behavior, and it sets up the moral corruption that a demon takes advantage of later in the script.

Why would we think those book sales are evil? After all, Depp is not doing aything illegal. He doesn't lie to them. He merely says "I can offer you this much for this book," and offers to get back to them later with offers on other books. Why do you think the audience boos and hisses at this behavior?

Ever hear of the stock market crash? That is why the rules are there. Without inside trading laws, as soon as the 'insiders' (which are generally high-level executives, not regular employees) realize that things are going badly (which they will always know before the public does) they can dump all their stock, making the price plummet, and the outsiders lose their shirts.

The major flaw with your premise (and your little story) is that you are looking at it in hindsight. In your story, Depp KNOWS that

OK, good, there's our problem and the source of our confusion. People have roundly condemned this deal because Gates knew EXACTLY how much DOS was going to be worth, down to the last dollar. What people have found so morally objectionable is that Gates already had the deal with IBM lined up by virtue of his mother's influence, and that he low-balled Kildall when Kildall did not know the entire story. Gates didn't look at Kildall's work and think, "Hmm, I bet I could sell this to someone," buy the program, take the risk, and then find a customer. People condemn this deal because Gates gave Kildall a haircut when there was NO risk, and by taking Kildall for a ride he would never have agreed to had everything been done aboveboard.

People pair this story with the Woz's "Breakout" story, where Steve Jobs got Wozniak to work four days straight to finish "Breakout," without telling him that Atari was offering a $5,000 bonus. Woz finished the work, Steve pocketed the money.

Neither story shows Gates or Jobs in a flattering light, and sometimes "being a sharp businessman" is just code for being a lousy human being.

How the hell did Gates know EXACTLY how much DOS was going to be worth? That is one incredibly stupid statement. The value of DOS is determined by how many copies were sold, and NOBODY knew how many that was going to be. IBM was entering an existing market, and that market was not exactly huge. Prior to the introduction of the PC there had been about 1.8M personal computers sold, mostly by Apple, Atari, and Radio Shack. And the PC was not exactly cheap, it cost over $3K with monitor, etc (at the time

I was there. EVERYONE foresaw the success of the IBM PC. No one ever got fired for buying IBM, remember? The IBM PC was long expected and highly anticipated. It was the closest thing to a sure bet as you ever get. The controversy wasn't over if the PC would be successful-- Apple had already demonstrated it was -- but over how much of IBM's mainframe business would be cannibalized by its introduction. When Apple took out a full-page ad welcoming IBM to the market, he pundits laughed, saying it was like the C

Past histories of Microsoft have said Mr. Allen's departure from the company was sparked by his first brush with cancer in 1982, when he was diagnosed with Hodgkin's disease.

In that year, Mr. Allen says he eavesdropped on a discussion in the Microsoft offices in Bellevue, Wash., between Mr. Gates and Steve Ballmer, now the company's CEO, in which he heard the two men talking about Mr. Allen's recent lack of productivity and how they might dilute his equity in the company by issuing options to themselves and other shareholders. Mr. Allen said he burst into the room and confronted Messrs. Gates and Ballmer, both of whom later apologized to him and backed down from their plan.

"I had helped start the company and was still an active member of management, though limited by my illness, and now my partner and my colleague were scheming to rip me off," he says in the book. "It was mercenary opportunism, plain and simple.".A spokesman for Microsoft said Mr. Ballmer had no comment.

Earlier efforts by Mr. Gates to whittle down his partner's stake in Microsoft were successful though, according to Mr. Allen.

Speaking conservatively, Bill Gates had access to IBM through his mother's business connections. Gary Kildall did not. Can we really claim to live in a meritocracy when the difference between billions and obscurity is who you were born to?

Moreover, can we agree that both physical strength and mental acuity begin as genetic traits? If we condemn a strong man for taking advantage of a weaker one, is that any different than a smart man taking advantage of a slower one? As a father, I don't allow my older son t

Did you have equal and fair access to the market without being an employee? Would the market have given both you and your employer a fair opportunity to sell that program, or can you not even get your foot in the door until you have capitulated and joined your employer's team?

Consider a real case from history. You're a farmer. Your produce is worth a great deal of money in the city. Knowing that the cities have need of food, you and the other farmers and people from the city paid taxes to a government to bu

We came up with the concept of a trust and passed laws against them (Sherman Anti-Trust Act, 1890) because we felt the behavior we were seeing, while not illegal in 1889, was wrong and should be prohibited. Enforcing the act had to wait for more than a decade until Roosevelt could get a court system that would act against the corporate interests. Indeed, the first application of the Act was to break Unions, not the trusts they were targeting.

Gates' story is that Kildall "went flying" instead of meeting with IBM, and thus missed out on the opportunity due to sloth.

Kildall's story is that Gates ripped him off.

Hmm, truth is neither of us were in the room that day. We're left to decipher what happened in the context of history. Which story makes more sense? Was Gary Kildall a lazy, shiftless screw-up like Gates says? Have we ever seen other instances where Gates acted in a less-than-ethical manner? Which story fits better?

What we KNEW is that Gates lied about having an OS ready to IBM, knowing of QDOS

Why are people so angry that Microsoft fulfilled a promise that it made? Gates said something to the effect of "I can get an OS just give me a few days" and that's exactly what he did. What's the problem? At least he followed through. How's HURD coming along?

and subsequently swindled QDOS from its creator, to fulfill his contract with IBM.

Swindled, lol. Let's be real, without Gates, Patterson would not have made money, not even the initial ~$100k he got from Microsoft, and no one would have ever heard of him. Yeah, Microsoft made a ton of money off the product by they also invested in it beyond the buyout and shouldered a ton of risk.

The real question is "Why did IBM even think Bill gates, a schoolboy at the time, might have an OS worth actually paying for without seeing it first.

Because Microsoft in 1980 was a prime developer of programming languages for the microcomputer?

Because MBASIC had become virtually synonymous with the eight-bit micro? Because it had a viable candidate for the *NIX market in XENIX? Because it had a red hot seller in the hardware market with the Z-80 SoftCard for the Apple II?

Because in five years it had gone from a two or three man company with revenues of $22,000 to a company with forty employees and revenues of $7.5 million?

Well of course they wouldn't have sold the product as cheaply if they had material knowledge of a pending deal the buyer had, but unless there was some disclosure requirement in the purchase agreement then they should have been told to GTFO.

I know everyone wants to believe the story that a devious Bill Gates simply changed the copyright message on a copy of CP/M and re-released it, but there are numerous issues with the story:

- CP/M is tiny. Really, really, small. And has a well documented API. Anyone conversant in 808x assembler can put together a clone in a matter of days. This isn't an academic statement, I put together one myself for a A Level Computer Science course in the 1980s when I wrote a "CP/M emulator" for the Sinclair QL as my final project. (Appropriately the Sinclair QL's native operating system is also called QDOS. Go figure.)

- QDOS wasn't even a direct clone. The largest - or at least most complex - component of CP/M is the file system - almost everything else is an almost 1:1 call to a BIOS routine. And QDOS didn't have CP/M's file system - it used FAT, not the somewhat inefficient CP/M system which, IIRC, required scanning the entire directory to determine where the free sectors were. So even if someone had started off with a copy of CP/M and directly ported it, 90% of it or more would have had to be rewritten to produce QDOS.

The stories of Gary Kildall typing in some obscure set of keystrokes causing a copy of PC DOS to announce that it was actually CP/M - haha! - always struck me as improbable, and the fact they only appeared in dubious sources several years after this had supposedly happened makes me think the stories are outright fabrications. That doesn't mean there weren't potential copyright issues, and I suspect most of the stories of IBM somehow settling with DR over the similarities have some elements of truth - but this is because this was the early eighties, the era of Pacman lawsuits, to be followed a few years later by Apple's infamous look and feel suits against DR and Microsoft/HP.

In terms of actual code being copied however - no. It would, arguably, have taken more work to translate CP/M into 8086 assembler and then make all of the changes necessary to turn it into QDOS than it would to write QDOS from scratch. QDOS had a similar API, and a similar but not identical shell. Otherwise it wasn't remotely similar.

CP/M is a very simple beast. It's laughable to think that anybody would go to the effort of disassembling it to find out how it worked then rewriting it function-for-function in 8086 assembly code. changing the file system as you go.

It would be much less work to just read the CP/M docs then write your own little OS using the ideas gleaned. I doubt he even did that. There was no magic in CP/M even way back then and MS-DOS isn't all that similar to it.

CP/M is a very simple beast. It's laughable to think that anybody would go to the effort of disassembling it to find out how it worked then rewriting it function-for-function in 8086 assembly code. changing the file system as you go.

It would be much less work to just read the CP/M docs then write your own little OS using the ideas gleaned. I doubt he even did that. There was no magic in CP/M even way back then and MS-DOS isn't all that similar to it.

More likely, people haven't understood the original dispute. Did QDOS steal lines of code from CP/M? Most likely not, but nobody ever claimed it did. Was it a rip-off of CP/M? Absolutely. QDOS implemented calls identically to CP/M with the specific aim of being as close to CP/M as possible. In other words, as Patterson him self said, he read through Kildalls manual and tried to create something that functioned identically.

As you point out however, he did a much better job on the FS, which is both to be commended, and also should be added on the "it was not a rip-off" side. DOS was an interrupt handler, and not much more though. As an interrupt handler it clearly "ripped off" CP/M to the point of being almost identical. However, not by stealing code. No stealing of code would have been needed (as you say) and that has never been asserted either. Not by the parties involved.

Was it a rip-off of CP/M? Absolutely. QDOS implemented calls identically to CP/M with the specific aim of being as close to CP/M as possible. In other words, as Patterson him self said, he read through Kildalls manual and tried to create something that functioned identically.

And also (as finally confirmed in the Google-Oracle case) copying an API is a perfectly reasonable thing to do.

...As an interrupt handler it clearly "ripped off" CP/M to the point of being almost identical....

Apparently it was made identical for the purpose of allowing Qdos to reuse Intel's CP/M-8 to CP/M-16 conversion scheme... From here... http://dosmandrivel.blogspot.com/ [blogspot.com]

My hope was that by making it as easy as possible to port existing 8-bit applications to our 16-bit computer...Intel had defined rules for translating 8-bit programs into 16-bit programs; CP/M translation compatibility means that when a program's request to CP/M went through the translation, it would become an equivalent request to DOS...So I made CP/M translation compatibility a fundamental design goal. This required me to create a very specific Application Program Interface that implemented the translation compatibility.

Jerry Pournelle is a seriously demented guy. I popped on to his blog last week where he and some equally daft people were insisting Special Relativity was wrong and that he still felt there was validity in the ether theory. No seriously, this guy (who did write some good military-themed SF back in the day), rejects much of 20th century physics in favor of a debunked classical theory that everyone knew had serious problems decades before Einstein came on the scene.

I'm about 90% sure you're wrong on this. CP/M's file system doesn't really resemble FAT at a low level. FAT actually originated as the file system implemented by Microsoft's early stand-alone BASIC implementations.

CP/M's file system was extremely crude, being comprised largely of a single table containing the directory, with the rest of the disk containing the data. Each directory entry contained pointers to up to 16 blocks, if a file contained more than that it had to have multiple directory entries.

FAT has multiple tablers, and FAT's system is, ultimately, based upon chains of clusters, and the directories simply point at the starting cluster, with the information about the groups of clusters themselves stored in a separate table (the actual FAT.)

They're both hideous, but they're not remotely similar.

did NOT need to scan the whole disk to put a filesystem together

I never said anything remotely similar.

What I said, which I believe is true, is that CP/M had to read the whole directory to find out what parts of the disk were empty. Many of the optimizations that occurred between 1.3 and 2.x were to address this specific issue.

The fact remains that he did die conveniently in a plane crash just after failing to come to terms with MS.

Not true.

On July 8, 1994, Kildall fell at a Monterey, California, biker bar and hit his head. The exact circumstances of the injury remain unclear; however, he had suffered problems with alcoholism in his later years. Various sources have claimed he fell from a chair, fell down steps, or was assaulted because he walked in to the Franklin Street Bar & Grill wearing Harley-Davidson leathers. He checked in and out of the hospital twice, and died three days later at the Community Hospital of Monterey Peninsula. The coroner's report identified the cause of death as blunt force trauma to the head. There was also evidence that he had experienced a heart attack, but an autopsy did not conclusively determine the cause of death.

Concurrent CP/M 3.1 and later, and single-user CP/M-86 with BDOS 3.3 and later (including DOS Plus), allow CP/M programs to access DOS-formatted discs via conventional BDOS calls, emulating (as far as possible) the behaviour of a normal CP/M filesystem. The behaviour is probably a good starting point for anyone writing a CP/M emulator which uses a hierarchical or non-CP/M filesystem.

From your link: "What is the evidence, then, that QDOS was a derivative work – a rip-off? The answer lies in the API, which describes how software can call up the underlying operating system and make it work for the user. The first 26 system calls of MS-DOS 1.0 are identical to the first 26 system calls of CP/M."

Yeah, just like Linux and WINE are rip-offs. The need to map system calls by number and not only name was of course due to the fact that the actual calling mechanism worked by number. However, the IEEE article is still strange, since the matters described are already settled. On the other hand, the legend of DOS being stolen and not only a clone lives on, in some places.

An API is a set of rules to communicate with another system, and a game (in the abstract sense) is a set of rules for an activity. What was deemed copyrightable in Tetris v. Xio was not only the block textures (your "copyrighted icon set") but also the specifics of the game rules themselves, such as the width of the playfield, the selection of the game pieces (use of all tetrominoes and only the tetrominoes as opposed to including smaller or larger polyominoes or polyplets), and how the game pieces behave

You may laugh, but remember that little dust-up with The SCO Group over precisely that claim? When it came time to actually show some evidence, they pointed to the identical lines in the header APIs that were part of the published Unix standards.

I think both this story, the dismissal and the original claim are all bollocks, especially due to the slanted language El Reg put on matters - "derived", "derivative work", "a rip-off".

Tim Paterson and Microsoft are essentially "guilty" of the same thing Google just won a court case against Oracle/Sun for - reimplementing an API. And yet Microsoft somehow comes off worse than Google for it...

Kildall lost out, Gates prospered - that's about the sum of it. Anything else is just farting in the wind. It does

Here's the good bit from The Register: However Zeidman contrives to ignore the incontrovertible evidence that MS-DOS was derived from CP/M, and instead establishes a straw man. Zeidman, who pictures himself in a deerstalker hat, asserts that he can refute the allegation that "Microsoft stole the CP/M source code" - a claim that has never been made, let alone contested.

Based on my own very limited historical knowledge, that's on-the-mark. I've heard many times over the years that MS-DOS was a clone of CP/M

Also most likely both would of been written in assembler at the time, the analysis is most likely flawed. On the other hand the creator of QDOS has already admitted that his was work did invole using a debugger on CP/M so it wasn't totally clean.

Always thought the issue was that MS did not have a license to re-license (e.g. to IBM) the product which was created by 'Seattle Computer Products'.

MS had bought all rights to it from SCP before the launch of the IBM PC. http://en.wikipedia.org/wiki/86-DOS#Creation_of_PC.C2.A0DOS [wikipedia.org] . This wasn't disputed by SCP, but they claim they wouldn't have sold it as cheap if they had known about the deal with IBM and pending launch of the IBM PC..

Seriously? Yes, MSDOS (and QDOS) were definitely inspired by CP/M. But it's hardly a big programming project is it? One bloke coding by himself could conceivably write a CP/M clone for Intel processors. I think that's probably the most obvious answer..

What next? Proof that the Apple II wasn't copied from the Commodore PET?

The PET was a much better design. And back then, it was all good... in fact, Chuck Peddle (inventor of the PET and the MOS 6502) actually helped Woz on some critical issues to get the Apple I up and running. But Peddle had a whole system approach, thus, all the other chips Commodore made to support the 6502. If you look at the Apple I/][ or may of the other early personal computers, you usually see a Microprocessor, some memory chips, and a vast sea of SSI and MSI parts from the TTL databook. If you look at early Commodore machines, you find all sorts of integration.

But there's a vast difference between "inspired by" and "copied". And even then, in layers. Steve Jobs saw the Xerox Alto and got inspired. Apple didn't really copy the UI, they actually left out some of the good stuff. And of course, the OS they created was vastly inferior, and the internals had nothing to do with the Xerox system. Microsoft did actually borrow some of Apple's stuff, but they's because they actually did exchange code. Most of Windows had nothing to do with MacOS, and the OS design was not something any experienced OS designer would have some up with (eg, the OS treating an application as a series of callbacks)... and that's not even counting all of the serialization Windows did in Win32 to prevent real multitasking.

Windows NT, on the other hand, was directly inspired by VAX/VMS (via Dave Cutler), but also ran a POSIX API layer from the get-go. But that was a standard by then, so no really a "copy" of UNIX anymore.

QDOS was actually quite similar to CP/M in it's structure, and CP/M86 was different in that it actually made use of the improvements offered in the 8086 processor. QDOS was written as if an 8080 to 8086 translator had been used to code it. However MS-DOS quickly moved away from this. What Microsoft sold was much polished over the original QDOS and CP/M OS's. They quickly improved the disk structure, FAT12 and FAT16 are different enough from the original CP/M disk structure. What they all STILL have in common is the use of the 0XE5 IBM uninitialized data marker in the FAT to show available space. This was a quick and dirty hack that allowed a freshly formated diskette to be used without having to initialize a directory structure on it.

First paragraph of wikipedia entry nicely sums up why this would be the case... that is, it was a clone that was ported to run on a different (albiet VERY similar) instruction set, a different file system and obviously different hardware support.

You'd think after that either:- not much of the original code with survive IF it was copied and then adapted- it was probably easier to copy the functionality and write from ground-up which is what this article implies

MS-DOS was a renamed form of 86-DOS – informally known as the Quick-and-Dirty Operating System or Q-DOS – owned by Seattle Computer Products, written by Tim Paterson.

Microsoft needed an operating system for the then-new Intel 8086 but it had none available, so it bought 86-DOS for $75,000 and licensed it as its own then released a version of it as MS-DOS 1.0. Development started in 1981, and MS-DOS 1.0 was released with the IBM PC in 1982.

86-DOS, in turn, was a clone of Digital Research's CP/M for 8080/Z80 processors ported to run on 8086 processors and with two notable differences compared to CP/M, an improved disk sector buffering logic and the introduction of FAT12 instead of the CP/M filesystem

Those accusations still sound like sour grapes from Gary Kildall. The Microsoft - IBM deal was genius. Gary sounds upset he did not have the foresight to make it happen.
He had his chance. Heck, MS even suggested that IBM talk to Gary and the CPM guys when they were looking for an operating system. But, Gary refused to play ball. Too bad.

So, Microsoft stepped up to the plate. They bought QDOS, worked with it and wrote MS-DOS. Sure, it was not an extraordinary operating system. But it wasn't terrible, and it worked like CP/M in a lot of ways because MS certainly took ideas from CP/M. That's perfectly OK (maybe not these days, software patents etc...) They were giving IBM and their customers what they wanted when Gary and Digital Research decided not to. That's the genius of Microsoft. Realizing the spectacular deal to be had and standing up to IBM to sign an agreement that would make them the biggest software company ever; keeping ownership of their software, regardless of how much big blue pushed them around. Sorry Gary, you missed out.

Lastly, I doubt the young Bill Gates would hypocritically allow his company to stoop to coping code after he wrote this [blinkenlights.com] and sent it to many of his future customers:

I would say the stooping started.. oh I don't know 1986? When MS got big and everyone got more rich and powerfull, the morally questionable and sometimes illegal stuff started happening. Stacker happend with DOS 6.0, which was like 1992, more than a decade of profits and power tripping after the inital IBM deal.

I'm sure the guys at Cisco or Apple (or any other like company) were all geeky and cool at first two, maybe pulling a few tricks here and there but playing the game.. then well.. we all know how i

The system calls and lots of the design are clearly cloned. Anyone who used both CP/M and MS-DOS back in the day and who dabbled in assembly language programming on both would be able to spot it.

If the software industry had been as rife with patents (both functional and design) and other litigation tools back then as it is today, Microsoft wouldn't have gotten away with this particular way of copying.

(Whether this is a good thing or a bad thing is left as an exercise for the reader.)

``The system calls and lots of the design are clearly cloned. Anyone who used both CP/M and MS-DOS back in the day and who dabbled in assembly language programming on both would be able to spot it.''

Back when CP/M was still kicking around, I had a Columbia Data Products XT-clone. It shipped with MS-DOS and CP/M-86 and I recall reading through the programming manual and thinking ``Geez this looks a lot like DEC's RT-11.'' Remember when MS-DOS used to ask you to insert the diskette containing COMMAND.COM? T

If the software industry had been as rife with patents (both functional and design) and other litigation tools back then as it is today, Microsoft wouldn't have gotten away with this particular way of copying.

If the legal situation with patents and copyrights had been that bad back then, we'd all still be stuck in the 8-bit era, and the Internet as we know it today wouldn't exist.

It seems highly hypocritical to criticize Bill Gates for cloning CP/M when we (rightly) defend similar actions taken in the pre

Where did this idea ever come from? "Everybody knows" that Gates bought QDOS from Kildall and nobody ever claimed that QDOS was a "copy of CP/M," not even Kildall himself. What was in dispute was whether Kildall was literally out to lunch or flying, or whatever, brushing off the meeting and selling a license for what turned out to be a pittance. That's the legend anyway, but he's not here on this planet anymore to defend himself.

Back in the day I had more than one machine I'd built (either 8080 or Z80 based) that ran CP/M, and I even wrote software (in C and in assembly language) to run under CP/M. MS-DOS only bore a superficial resemblance to CP/M, in that there are certain elements to a command-line OS that you really can't easily get around.

More interesting the is the tale of how Windows 3.11 did the DOS version check to determine if it was compatible, back around 1992 or so. I recall reading an analysis of how Windows managed to throw a nasty message if DR DOS was used instead of DOS. Apparently the Windows code was actually encrypted or something to obscure the hoops they were jumping through so that Microsoft could destroy DR DOS.

"MS will pay SCP $10,000 upon signing of this agreement Payment of the initial fee described in Paragaph 2(c), above and royalties called for under this Agreement shall be due within 45 days of the date MS invoices their customer for the product for which the initial fee or royalty is due" link [edge-op.org]

DOS caught on because DOS was sold by MS at half the price of the closest rival

No, DOS caught on because it was the OS for IBM's PCs, and "nobody ever got fired for buying IBM." Back in those days, there were no compatible computers. Also, there was Lotus on the IBM, and every business needs a good spreadsheet.